Many people running Java applications use the servlet engine to serve static content as well. But no servlet engine is nearly as efficient as LiteSpeed Web Server for these processes. In order to improve the overall performance, LiteSpeed Web Server can be configured as a gateway server, which serves static content and forwards dynamic Java page requests to the servlet engine.

LiteSpeed Web Server requires certain contexts to be defined in order to run a Java application. A Java Web App Context automatically creates all required contexts based on the Java web application's configuration file (WEB-INF/web.xml).

There are a few points you need to keep in mind when setting up a Java Web App Context:

A Servlet Engine external application must be set up in External Application before Java Web App Context can be set up.

If the web application is packed into a .war file, the .war file must be expanded. The server cannot access compressed archive files.

For the same resources, the same URL should be used no matter whether it is accessed through LiteSpeed Web Server or through the servlet engine's built-in HTTP server. For example, Tomcat 4.1 is installed under /opt/tomcat. Files for the "examples" web application are located at /opt/tomcat/webapps/examples/. Through Tomcat's built-in HTTP server, the "examples" web application is thus accessed with a URI like "/examples/***". The corresponding Java Web App Context should thus be configured: URI = /examples/, Location = /opt/tomcat/webapps/examples/.

URI

Description

Specifies the URI for this context. The URI should start with a "/". If a URI ends with a "/", then this context will include all sub-URIs under this URI.

Syntax

URI

Location

Description

Specifies the directory that contains the files for this web application. This is the directory containing "WEB-INF/web.xml".

Syntax

path

Servlet Engine

Description

Specifies the name of the servlet engine that serves this web application. Servlet engines must be defined in the External Application section at the server or virtual host level.

Syntax

Select from drop down list

Enable Expires

Description

Specifies whether to generate an Expires header for static files. If enabled, an Expires header will be generated based on Expires Default and Expires By Type.

Specifies default settings for Expires header generation. This setting takes effect when Enable Expires is set to "Yes". It can be overridden by Expires By Type. Do not set this default at the server or virtual host level unless you have to, since it will generate Expires headers for all pages. Most of time this should be set at the context level for certain directories that do not change often. If there is no default setting, no Expires header will be generated for types not specified in Expires By Type.

Syntax

A|Mseconds The file will expire after base time(A|M) plus specified seconds. Base time "A" sets the value to the client's access time and "M" to the file's last modified time.

Expires By Type

Description

Specifies Expires header settings for individual MIME types.

Syntax

Comma delimited list of "MIME-type=A|Mseconds". The file will expire after base time (A|M) plus specified seconds.

Base time "A" sets the value to the client's access time and "M" to the file's last modified time. MIME-type accepts wildcard "*", like image/*.

Extra Headers

Description

Specifies extra response headers to be added. Multiple headers can be added, one header per line. Put "NONE" to disable headers inherited from parent content.

Syntax

"[HeaderName]: [HeaderValue]" in each line.

Example

Cache-control: no-cache, no-store My-header: Custom header value

Auto Index

Description

Specifies whether to generate a directory index on the fly when index files listed in Index Files are not available in a directory. This option is customizable at the virtual host and context level, and is inherited along the directory tree until it is explicitly overridden. You can customize the generated index page. Please check online wiki How-tos.

Syntax

Select from radio box

Tips

[Security] It is recommended to turn off Auto Index wherever possible to prevent revealing confidential data.

Specifies names of index files that will be searched sequentially when a URL is mapped to a directory. You can customize it at the server, virtual host, and context level.

Syntax

Comma-delimited list of index filenames.

Tips

[Performance] Only set index files that you need.

Realm

Description

Specifies the authorization realm for this context. When specified, a valid username and password must be provided in order to access this context. Authorization Realms are set up in the Virtual Host Security section. This setting uses each realm's Realm Name.

Syntax

Select from drop down list

Authentication Name

Description

Specifies an alternative name for the authorization realm for the current context. If not specified, the original realm name will be used. The authentication name is displayed on the browser's login pop-up.

Require (Authorized Users/Groups)

Description

Specifies which user/group can access this context. This allows you to use one user/group database (specified in Realm) across a number of contexts, but only allow certain users/groups from that database to access this context.

group groupid [groupid ...] Only users belonging to the listed groups can access this context.

If this setting is not specified, all valid users will be allowed to access this resource.

Access Allowed

Description

Specifies which IPs or sub-networks are allowed to access resources under this context. Together with Access Denied and server/virtual host level access control, accessibility is determined by the smallest scope that a client's IP address falls into.

Syntax

Comma-delimited list of IPs/sub-networks.

Example

Sub-networks can be written as 192.168.1.0/255.255.255.0, 192.168.1, or 192.168.1.*.

Access Denied

Description

Specifies which IPs or sub-networks are NOT allowed to access resources under this context. Together with Access Allowed and server/virtual host-level access control, accessibility is determined by the smallest scope that a client's IP address falls into.

Syntax

Comma-delimited list of IPs/sub-networks.

Example

Sub-networks can be written as 192.168.1.0/255.255.255.0, 192.168.1, or 192.168.1.*.

Authorizer

Description

Specifies an external application that can be used to generate authorized/unauthorized decisions. Currently, only the FastCGI Authorizer is available. For more details about the FastCGI Authorizer role, please visit http://www.fastcgi.com.

Syntax

Select from drop down list

Add Default Charset

Description

Specifies whether to add a character set tag to the "Content-Type" response header, when content type is either "text/html" or "text/plain" without any parameters. When set to Off, this function is disabled. When set to On, either the character set specified by Customized Default Charset or the default "iso-8859-1" will be added.